drivers/platform/x86/samsung-q10.c

   1 /*
   2  *  Driver for Samsung Q10 and related laptops: controls the backlight
   3  *
   4  *  Copyright (c) 2011 Frederick van der Wyck <fvanderwyck@gmail.com>
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License version 2 as
   8  *  published by the Free Software Foundation.
   9  *
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/kernel.h>
  14 #include <linux/init.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/backlight.h>
  17 #include <linux/dmi.h>
  18 #include <linux/acpi.h>
  19
  20 #define SAMSUNGQ10_BL_MAX_INTENSITY 7
  21
  22 static acpi_handle ec_handle;
  23
  24 static bool force;
  25 module_param(force, bool, 0);
  26 MODULE_PARM_DESC(force,
  27                 "Disable the DMI check and force the driver to be loaded");
  28
  29 static int samsungq10_bl_set_intensity(struct backlight_device *bd)
  30 {
  31
  32         acpi_status status;
  33         int i;
  34
  35         for (i = 0; i < SAMSUNGQ10_BL_MAX_INTENSITY; i++) {
  36                 status = acpi_evaluate_object(ec_handle, "_Q63", NULL, NULL);
  37                 if (ACPI_FAILURE(status))
  38                         return -EIO;
  39         }
  40         for (i = 0; i < bd->props.brightness; i++) {
  41                 status = acpi_evaluate_object(ec_handle, "_Q64", NULL, NULL);
  42                 if (ACPI_FAILURE(status))
  43                         return -EIO;
  44         }
  45
  46         return 0;
  47 }
  48
  49 static const struct backlight_ops samsungq10_bl_ops = {
  50         .update_status  = samsungq10_bl_set_intensity,
  51 };
  52
  53 static int samsungq10_probe(struct platform_device *pdev)
  54 {
  55
  56         struct backlight_properties props;
  57         struct backlight_device *bd;
  58
  59         memset(&props, 0, sizeof(struct backlight_properties));
  60         props.type = BACKLIGHT_PLATFORM;
  61         props.max_brightness = SAMSUNGQ10_BL_MAX_INTENSITY;
  62         bd = backlight_device_register("samsung", &pdev->dev, NULL,
  63                                        &samsungq10_bl_ops, &props);
  64         if (IS_ERR(bd))
  65                 return PTR_ERR(bd);
  66
  67         platform_set_drvdata(pdev, bd);
  68
  69         return 0;
  70 }
  71
  72 static int samsungq10_remove(struct platform_device *pdev)
  73 {
  74
  75         struct backlight_device *bd = platform_get_drvdata(pdev);
  76
  77         backlight_device_unregister(bd);
  78
  79         return 0;
  80 }
  81
  82 static struct platform_driver samsungq10_driver = {
  83         .driver         = {
  84                 .name   = KBUILD_MODNAME,
  85                 .owner  = THIS_MODULE,
  86         },
  87         .probe          = samsungq10_probe,
  88         .remove         = samsungq10_remove,
  89 };
  90
  91 static struct platform_device *samsungq10_device;
  92
  93 static int __init dmi_check_callback(const struct dmi_system_id *id)
  94 {
  95         printk(KERN_INFO KBUILD_MODNAME ": found model '%s'\n", id->ident);
  96         return 1;
  97 }
  98
  99 static struct dmi_system_id __initdata samsungq10_dmi_table[] = {
 100         {
 101                 .ident = "Samsung Q10",
 102                 .matches = {
 103                         DMI_MATCH(DMI_SYS_VENDOR, "Samsung"),
 104                         DMI_MATCH(DMI_PRODUCT_NAME, "SQ10"),
 105                 },
 106                 .callback = dmi_check_callback,
 107         },
 108         {
 109                 .ident = "Samsung Q20",
 110                 .matches = {
 111                         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG Electronics"),
 112                         DMI_MATCH(DMI_PRODUCT_NAME, "SENS Q20"),
 113                 },
 114                 .callback = dmi_check_callback,
 115         },
 116         {
 117                 .ident = "Samsung Q25",
 118                 .matches = {
 119                         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG Electronics"),
 120                         DMI_MATCH(DMI_PRODUCT_NAME, "NQ25"),
 121                 },
 122                 .callback = dmi_check_callback,
 123         },
 124         {
 125                 .ident = "Dell Latitude X200",
 126                 .matches = {
 127                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 128                         DMI_MATCH(DMI_PRODUCT_NAME, "X200"),
 129                 },
 130                 .callback = dmi_check_callback,
 131         },
 132         { },
 133 };
 134 MODULE_DEVICE_TABLE(dmi, samsungq10_dmi_table);
 135
 136 static int __init samsungq10_init(void)
 137 {
 138         if (!force && !dmi_check_system(samsungq10_dmi_table))
 139                 return -ENODEV;
 140
 141         ec_handle = ec_get_handle();
 142
 143         if (!ec_handle)
 144                 return -ENODEV;
 145
 146         samsungq10_device = platform_create_bundle(&samsungq10_driver,
 147                                                    samsungq10_probe,
 148                                                    NULL, 0, NULL, 0);
 149
 150         return PTR_ERR_OR_ZERO(samsungq10_device);
 151 }
 152
 153 static void __exit samsungq10_exit(void)
 154 {
 155         platform_device_unregister(samsungq10_device);
 156         platform_driver_unregister(&samsungq10_driver);
 157 }
 158
 159 module_init(samsungq10_init);
 160 module_exit(samsungq10_exit);
 161
 162 MODULE_AUTHOR("Frederick van der Wyck <fvanderwyck@gmail.com>");
 163 MODULE_DESCRIPTION("Samsung Q10 Driver");
 164 MODULE_LICENSE("GPL");